Booster apparatus for conveyer drives



Feb. 19, 1952 e. G. ERLAND ETAL 2,586,

BOOSTER APPARATUS FOR CONVEYER DRIVES Filed March 21, 1949 3 Sheets-Sheet 1 FlELi. /9 26 0 O 0 0 0 cal-lib 0 0 0 9 0 0 6 Q --7( /2 /7 20 o w 2/ 2 1 /7 Inventors:

605mm". 67'. fem/v0 am 41954 5. P5455014 Feb. 19, 1952 G. G. ERLAND ETAL BOOSTER APPARATUS FOR CONVEYER DRIVES 3 Sheets-Sheet 2 Filed March 21, 1949 Feb. 19, 1952 G. e. ERLAND ETAL 2, 8 ,6

BOOSTER APPARATUS FOR CONVEYER DRIVES Filed March 21, 1949 3 Sheets-Sheet 5 176067710729. fiufimrfd fem/v0 and H12? 5. Paw/350w,

fie/2' 4/70/7754 FIEJL Patented Feb. 19, 1952 BOOSTER APPARATUS 'FOR CONVEYER DRIVES Gustave G. Erland and Axel B..Pearson, Pittsburgh, Pa., :assignors to United .States .Steel Company, a corporation of New'Jersey Application March 21, 1949, Serial No. 82512 This invention relates to vimproved booster apparatus for initiating movement of conveyors and the like.

Heavily loaded conveyors' require a largestarting force to overcome inertia of the load, but

:'once this inertia is overcome a much smaller ierce 'issu'ihcient'to maintain movement. Conse- "quently it 'isuneconomical to equip such con- -=veyors with drive motors -of 'sufiicient size to overcome the starting inertia; instead it is preferred'to employseparate'boosters for this purpose.

'An object of the present invention is to provide "improved boosterapparatuswhich is of simple, azconomical and rugged construction and is capable of initiating conveyor movement more efii- =cienuy than previous such apparatus with which i'we'are familiar.

-A further "object of the invention is'to provide -'improvedbooster apparatus which is operated by fluid pressure means and which on actuation 'er'iga'gesthe conveyor to'furnis'h the initial starting force and which subsequently automatically freturns to its original position.

A further object of the invention is toprovide improved booster apparatus which embodies a carriage beneath a conveyor 'fiight, retractable dogs mounted on the carriage "for engaging the conveyor, and fiuid pressure means which both propels the carriage and automatically :projects 'orretracts .the'dogs, depending on the direction "of propulsion.

y In accomplishing these and other objects of f thefinvention; we' have provided improved 'details of "structure; a preferred form of which isshown in the accompanying drawings, :in "which:

Figure 1 is a side elevationalview ofan endless chain conveyor equipped'with'an improved boostjer apparatus embodying features of the present invention;

.Figurezis a topplan view of the booster'apparatus;

.Figure 3 is a vertical longitudinal sectional view taken substantially on line III-'III of Figure and :F gure .4 .is a vertical cross-sectional view taken substantially on .line IVIV of Figure 3.

In the drawing there is shown an endless chain :conveyor of any standard construction adapted to transport .heavy loads. The particular con- ,veyorlillustrated comprises plates ID and axles 5 '12 to which the plates are hinged. As hereint'iafter explained, the booster apparatus of the present invention engages said axles. As best shown iinFigure 4 thimbles' l3' of hardened steel v 'surround'said axlesin thereg'ions thus "engaged 10 Claims. (Cl. :198203-) Cal to reduce wear. The :outer ends 10f .the axles acarry flangedwheels M which, along the upper 'fiigh't'of the conveyor, :ride on a pair of :rails 45 and along the lower flight-on asimiIar pairaof rails not shown. The :conveyor issupportedon aaframework which comprises upright posts .16,

- horizontalzcross beams 1-1, and longitudinalkbeams 'JIBOII which-rails 2|,5 are mounted. The conveyor is driven by .any suitable drive means, not shown,

.10 and the :upper flight :carries the-load and travels from .leftzto .right.

A booster apparatus :constructedinaccordance with the-present invention is supported on the .:conveyor "framework between the 'two "conveyor 10 ifiights. .Thisiapparatus comprises a reciprocable 'icarriage [9 which .has wheels '20 adajacent its ends. The. wheels :ride :in trackways 21 which are carried ="on longitudinal pbeams -:l 8 :of the 32011- veyor framework. "The length of :the "trackways is such that the :carriage :can travel a sufiicient distance to accelerate the conveyor :to

the speed at which it is driven by the 'driveimotor.

A 'main "fluid pressure cylinder .22, either Shydraulic or pneumatic, is supported tin aLStatioIIar-y position on the conveyor framework Ebetweenthc conveyor flights forwardly or "to the right of "trackways 2 I '(Figure 1) .The cylinder :is shown as carried on auxiliary longitudinal beams :24

extending between one pair of cross :beams II?! of the framework. A 'pull back fluidwpressure cylinder 25, of smaller diameter than the: main cylinder and also either hydraulic or pneumatic, is supported in i a stationary position on the =conveyor 'framework between the conveyor flights 'rearwardly or to the left of trackways 21 The mounting means for the pull back cylinder conveniently is similar to that f or "the main 1 cylinder and-hence is not described in detail.

As best shown in'Figure 3, an'upright lever is carried ona shaft' 2l-which 'is" journaled*to the underside'of-carriage IS "in bearings 21a. The

main cylinder hasa reciprocable piston to which a mainpiston rod 28=is joined. Lever26 extends through a slot 29 in the "carriagefioor and is connected to this piston'rod through a fitting "30 so thatreciprocable "movement of "the'pist'on rod rotates "shaft 21. The connection between thefitting'and the leverdssufiiciently loose that it :enables -straight 'line'movement of the piston roditorotate the shaft through the necessary small arc. Rotation of the "shaft islimited-"by engagement of lever .26 with the ends "of "slot 29.

A pair of vertically "movable dog supports *3! arej mounted "adjacent opposite sidesofpan ag l9 The mounting means includes bracke'ts 32.

which depend below the carriage floor, and springs 33, which are interposed between the brackets and the dog supports and urge the latter upwardly. The lower end portions of said dog supports contain slot 34 and shaft 21 carries a pair of laterally extending arms 26a which have pins 35 that ride in said slots. Thus the assembly of shaft 21 and levers 26 and 26a may be considered a bell crank, which operatively connects the piston rod and the dog supports. Dogs 35 are pivoted to thedog supports and at their lower ends are adapted to abut stops 3! at the forward end of said supports so that they can pivot clockwise, but not counter-clockwise, from their upright position. The upper end of the dogs preferably carry rollers 38.

Thus it is seen that movement of piston rod 28 to the right rotates the bell crank clockwise to the limit permitted by engagement of lever 26 with the forward end of slot 29. Such rotation of the bell crank enables springs 33 to lift dog supports 3i and dogs 36 to the limit permitted by engagement of the lower ends of slots 34 with pins 35. When thus projected, the dogs are in position to engage thimbles l3'on axles I2 of the conveyor for applying a motivating force thereto. If the dogs happen to be directly underneath an axle when they are projected, rollers 38 engage the axle and pivot the dogs clockwise. The lower end portions of the 'dogs' overbalance the dogs about their'piv'ots so that subsequent forward movement of the carriage returns the dogs to the upright position where they can engage the next axle. 'After the main piston projects the dogs and the latter are in engagement with an axle, continued movement of the piston to the right pulls the'conveyor and thus starts it in'motion. In usual operation the conveyor drive motor starts promptly afterthe cylinder is actuated and takes over the driving as soon as the booster'apparatus furnishes the initial acceleration.

For returning the booster apparatus 'to its original position and retracting the dogs, pullback cylinder 25 has a piston and piston rod 39 which are connected to lever 26-of the bell crank. The connecting means includes a fitting 40 joined to the end of the rod, a link M joined to said fitting, and a pair of laterally spaced links 42 joined to link 4! and to the bell crank lever. In usual operation a controlledpressure is maintained constantly in cylinder 25 and always tends to move piston rod 39 to the left. Pressure applied to cylinder 22 for moving the carriage to the right and starting the conveyor overcomes this pressure in cylinder 25. When pressure in cylinder 22 is released at the conclusion of a carriage stroke, the pressure in cylinder 25 furnishes a positive means both for returning the carriage and also for rotating the bell crank counter-clockwise and thus automatically retracting the dog supports and dogs. 'Thus the dogs are removed from the path of movement of the conveyor axles and do not interfere with conveyor travel. However, if an axle should happen to collide with the dogs, the latter merely pivot clockwise and there is no damage.

While we have shown separate single acting main and pull-back cylinders, it is apparent that a double acting main cylinder couldaccomplish similar purposes and thus the pull-back cylinder could be eliminated. Nevertheless .we have found in practical installations that the two-cylinder arrangement is a more economical and efficient construction and therefore is preferred. The

main cylinder is relatively large and the pullback cylinder is much smaller. It appears more economical to provide the additional small cylinder than to make the large cylinder .double acting.

From the foregoing description it is seen we have provided a booster apparatus of simple and rugged construction and one which is readily adapted to start loads of any magnitude merely through use of appropriate pressures. The mechanism can be made largely automatic in its operation by use of proper control means coordinated with the conveyor drive.

While we have shown and described only a preferred embodiment of the invention, it is apparent that modifications may arise. Therefore, we do not wish to be limited to the disclosure set forth but only by the scope of the appended claims.

We claim:

1. A booster aparatus for starting conveyors and the like comprising a carriage, retractable means on said carriage adapted when projected to engage a conveyor and when retracted toclearthe conveyor, means for propelling said carriage, a mechanical linkage connecting said propelling means and said retractable means for automatically projecting the latter as the carriage is propelled, and means connected to said linkage for returning said carriage to its original positionv and automatically retracting said retractable means as the carriage is returned, said'carriagereturning means and linkage holding said retractable means in its retracted position until again projected by said propelling means.

' 2. A booster apparatus for starting conveyors and the like comprising a carriage,-a retractable dog supported on said carriage and adapted when projected to engage a conveyor for applying a motivating force thereto and when retracted to clear the conveyor, fluid pressure means for propelling said carriage, a mechanical linkage connecting said fluid pressure means and said dog for automatically projecting the latter as said fluid pressure means commences to propel the carriage, and means connected to said linkage for returning said carriage to its original position and automatically retracting said dog at the start of the carriage return, said carriage-returning means and linkage holding said dog in its retracted position until again projected by said fluid pressure means. a

3. A booster apparatus for starting conveyors and the like comprising a carriage, retractable dogs supported on said carriage and adapted when projected to engage a conveyor for applying a motivating force thereto and when retracted to clear the conveyor, a bell crank pivoted to said carriage for rotation through a limited arc and operatively connected with said dogs for, projecting and retracting the latter, fluid pressure means operatively connected with said bell crank for rotating the latter and thus Projecting said dogs and for propelling said carriage, and means operatively connected with said bell crank for rotating the latter back to its original position and thus retracting said dogs and for returning said carriage to its original position, said dogs remaining in their retracted position until said fluid pressure means again projects them. i

l. A booster apparatus for starting conveyors and the like comprising a carriage, retractable dog supported mounted on said carriage, dogs pivoted to said dog supports and adapted when said dog supports are projected to engage a conveyor for applying, a motivating forcethereto, a bell crank r pivoted; :twsaicb carriagerrfonxrotatiomthrough a limited are and having an arm. operatit'.el35 connected with said dog -supportsandlaisecond arm,

a stationary main fluid pressure cylinder, a main pistoncand piston rod mounted for reciprocable movement in said main-cylinder and operatively ccnne'cted'with thesecond armof said bell crank for rotating said bell crank and thus projectingsaid dog supports and for propelling said car riage, and means for returning said carriage an retracting said dog supports. '"1 5. A booster apparatus for starting conveyors and the like comprising a carriage, retractable" dog supports mounted on said carriage, dogs piv-;,; oted to said dog supports and adapted when said dog supports are projected to engage a conveyor for applying a motivating force thereto, a bell crank pivoted to said carriage for rotation through a limited arc and having an arm ope tively connected with said dog supports and *a second arm, a stationary main fluid pressure cylinder, a main piston and piston rod mounted-for I reciprocable movement in said main cylinder and projecting said dog supports and for propelling A operatively connected with the second arm of said bell crank for rotating said bell crank and thus said carriage, a stationary pull-back fluid pressure cylinder, and a pull-back piston and piston] rod mounted for reciprocable movement in said pull-back cylinder and operatively connected with the second arm of said bell crank for rotating said bell crank in the opposite direction from said main piston and piston rod and thus retracting said dog supports and for returning said carriage.

veyor comprising a carriage supported on the c veyor framework to travel beneath a flight ofgthe conveyor, retractable means on said carriage, said retractable means when retracted clearing the conveyor and when projected engaging the eo f veyor, means for propelling said carriage, a n 'l e chanical linkage connecting said propelling means and said retractable means for automatically pro-g jecting the latter as the carriage is propelled, and means connected to said linkage for returning said carriage to its original position and auto matically retracting said retractable means arter the conveyor has accelerated to the speed at which it is driven by said drive means, said ,car riage-returning means and said linkage holding said retractable means in its retracted post 11" until again projected by said propelling mea 7. In combination with an endless chain veyor having a supporting framework and a, e means, a booster apparatus for starting thejtgonveyor comprising a carriage supported on 'the conveyor framework to travel beneath a flight of the conveyor, a retractable dog supported on said carriage, said dog when retracted clearing the conveyor and when projected engaging the ,conveyor for applying a motivating force thereto, fluid pressure means for propelling said carriage, a mechanical linkage connecting said fluid pres? sure means and said dog for automatically pro jecting the latter as said fluid pressure means commences to propel the carriage, and means connected to said linkage for returning said carriage to its original position and automatically retracting said dog after the conveyor has accel erated to the speed at which it is driven by said drive means, said carriage-returning means and said linkage holding said dog inits retracted positiona-untiliagain projected by-- said fiuidmmsmre means-i combination with an "endless cham' con- 1 veyor having a supporting-frameworkand aydrive means, a booster apparatus for starting the conveyor comprising a carriage supported on the conveyors-framework-to travel beneath a flight of the conveyor,retractable-dogs supported on said carriage, said dogs when retracted clearing said conveyor and when projected engaging said conveyor for applying a motivating force thereto, a bell crank pivoted to said carriage for rotation through a limited arc and operatively connected with said dogs for projecting and retracting the latter, fluid pressure means operatively connected with said bell crank for rotating the latter and thus projecting said dogs and for propelling said carriage, and means operatively connected with said bell crank for rotating the latter back to its original position and thus retracting said dogs and for returning said carriage to its original position, said dogs remaining in their retracted position until said fluid pressure means again projects them.

9. In combination with an endless chain conveyor having a supporting framework and a drive means, a booster apparatus for starting the conveyor comprising a carriage supported on the conveyor framework to travel beneath a flight of the conveyor, retractable dog supports mounted on said carriage, dogs pivoted to said dog supports and adapted when said dog supports are projected to engage the conveyor for applying a motivating force thereto, a bell crank pivoted to said carriage for rotation through a limited arc and having an arm operatively connected with said dog supports and a second arm, a main fluid pressure cylinder fixed to the conveyor framework, a main piston and piston rod mounted for reciprocable movement in said main cylinder and operatively connected with the second arm of said bell crank for rotating said bell crank and thus projecting said dog supports and for propelling said carriage and thus starting the conveyor, and means for returning said carriage and retracting said dog supports after the conveyor has been accelerated to a speed at which it can be driven by said drive means.

. 10. In combination with an endless chain con- 0 veyor having a supporting framework and a drive means, a booster apparatus for starting the conveyor comprising a carriage supported on the conveyor framework to travel beneath a flight of the conveyor, retractable dog supports mount- 55 ed on said carriage, dogs pivoted to said dog supports and adapted when said dog supports are projected to engage the conveyor for applying a.

motivating force thereto, a bell crank pivoted to said carriage for rotation through a limited are 0 and having a laterally extending arm operatively connected with said dog supports and an upright arm, a main fluid pressure cylinder fixed to the conveyor framework, a main piston and piston rod mounted for reciprocable movement in said main cylinder and operatively connected with the upright arm of said bell crank for rotating said bell crank and thus projecting said dog supports and for propelling said carriage and thus starting the conveyor, a pull-back fluid pressure cylinder fixed to the conveyor framework, and a.

pull-back piston and piston rod mounted for reciprocable movement in said pull-back cylinder and operatively connected with the upright arm of said bell crank for rotating said bell crank in the opposite direction from said main piston and.

piston rod and thus retracting said dog supports and for returning said carriage after the conveyor has been accelerated to a speed at which it can be driven by said drive means.

GUSTAVE G. ERLAND.

AXEL B. PEARSON.

The following references are of REFERENCES organ,

I record in the file of this patent:- I i NITED STATES PATENTS Number Name Date 1,522,116 Gray et a1. Jan. 6, 1925 1,934,835. Weiss 4.0;. Nov. .14, 1933 

